Preheat your oven to 375°F (190°C) and lightly grease a baking dish.
Heat olive oil in a pan over medium heat. Sauté the onion and garlic until softened. Add the black beans, rice, corn, cumin, chili powder, salt, and pepper. Stir well, then remove from heat and mix in ½ cup of the shredded cheese.
Spoon 2-3 tablespoon of the filling onto each tortilla, roll tightly, and place seam-side down in the baking dish.
Mix the enchilada sauce with oregano and cayenne, then pour evenly over the enchiladas. Sprinkle with 1 cup of shredded cheese.
Bake for 20-25 minutes until the cheese is melted and bubbly.
Let cool slightly, then top with fresh cilantro, sliced avocado, crumbled queso fresco, and red chili slices. Optionally add a layer of Greek yogurt and serve with lime wedges.